As structures have become more complex, the analysts were forced to approximations of closed-form solutions, experimentation or numerical methods. In particular with the advent of digital computers many numerical techniques used in engineering applications have been developed. Numerical techniques generally employ a method which discretizes the continuum of the structural system into a finite collection of points by means of mathematical relations from elasticity. The most common technique is the finite element method (FEM) which allows accurate representation of complex geometry, inclusion of dissimilar material properties, user-friendly representation of the total solution and capture of local effects. Once the numerical results have been obtained, in order to understand if they have a real confirmation, experimental tests are set up.